PROJECT SUMMARY/ABSTRACT Substance use disorders among individuals living with HIV/AIDS are highly prevalent and problematic, leading to decreased retention in care, medication adherence, and viral suppression and significantly increasing the risk of new HIV infections. Wide recognition of the prevalence and problematic nature of comorbid HIV/AIDS and substance use disorders has led to urgent calls to improve substance use disorder service integration (SUDSI) within HIV/AIDS settings. However, despite more than a decade of calls to improve SUDSI within AIDS Service Organizations (ASOs), this remains an urgent need. As such, a key impetus for the proposed application is the need to improve SUDSI within ASOs (urgent need #1). Another key impetus for this application is the broader and arguably more urgent need to improve generalizable knowledge regarding how best to advance empirically based innovations along the Exploration, Preparation, Implementation, Sustainment (EPIS) continuum within real-world settings (urgent need #2). To address these two urgent needs, our research team will achieve two specific aims. Specific Aim 1 will empirically identify stakeholder-driven Substance-Treatment-Strategy (STS) recommendations for improving SUDSI within ASOs across the nation. More specifically, three sequential Real-Time Delphi's will be conducted to empirically identify multiple substance (e.g., alcohol), treatment (e.g., motivational interviewing), strategy (e.g., workshop training + feedback + coaching) combinations for substances found to negatively impact the HIV care continuum. Specific Aim 1 is significant because it will result in STS recommendations that will guide hundreds of ASOs across the United States towards improving SUDSI within their organization (urgent need #1). Specific Aim 2 will experimentally test the incremental effectiveness of external facilitation (EF; A process of interactive problem solving and support that occurs in a context of a recognized need for improvement and a supportive interpersonal relationship) for improving the advancement of empirically based innovations (i.e., the STS recommendations) along the EPIS continuum beyond what can be achieved via usual dissemination (i.e., mail, email, website postings). Aim 2 is significant because systematic reviews have concluded that such usual dissemination strategies are important yet insufficient ways to disseminate empirically based innovations beyond the exploration phase of the EPIS continuum. Additionally, although evidence supports external facilitation during the EPIS continuum's middle two phases (preparation, implementation), no research has experimentally tested the extent to which external facilitation can be effective during the critical exploration phase, especially not in terms of its incremental effectiveness beyond what is achieved via usual dissemination. Thus, Aim 2 has additional significance given it will advance generalizable knowledge regarding how best to move empirically based innovations from the EPIS model's exploration phase to subsequent EPIS model phases within real-world settings (urgent need #2).